Fix Python 3.12 flake8 compatibility: upgrade importlib-metadata to >=6.0.0

- Fixes AttributeError: 'EntryPoints' object has no attribute 'get'
- importlib-metadata 6.0.0+ has the updated EntryPoints API for Python 3.12
- This should resolve the flake8 compatibility issues with pytest-flake8

Author: JustinWonjaePark

requirements-dev.txt

@@ -1,9 +1,9 @@
 tox
 pytest
 pytest-cov
-pytest-flake8
-flake8==3.9.2
+pytest-flake8>=1.1.0
+flake8>=5.0.0
 dataclasses
 scanoss
-importlib-metadata==4.12.0
+importlib-metadata>=6.0.0
 pytest-xdist